c1: warnings being treated as errors
ephoto_imaging.c: In function hsv_to_rgb:
ephoto_imaging.c:54: warning: implicit declaration of function round
ephoto_imaging.c:54: warning: incompatible implicit declaration of built-in function round
ephoto_imaging.c:73: warning: incompatible implicit declaration of built-in function round
ephoto_imaging.c:80: warning: incompatible implicit declaration of built-in function round
ephoto_imaging.c:87: warning: incompatible implicit declaration of built-in function round
ephoto_imaging.c:94: warning: incompatible implicit declaration of built-in function round
ephoto_imaging.c:101: warning: incompatible implicit declaration of built-in function round
ephoto_imaging.c:108: warning: incompatible implicit declaration of built-in function round
make[1]: *** [ephoto-ephoto_imaging.o] Error 1